The Impact of Positive-Definite Moisture Transport on NWP Precipitation Forecasts
نویسندگان
چکیده
A positive-definite transport scheme for moisture is tested in a nonhydrostatic forecast model using convection-permitting resolutions. Use of the positive-definite scheme is found to significantly reduce the large positive bias in surface precipitation forecasts found in the non-positive-definite model forecasts, in particular at high precipitation thresholds. The positive-definite scheme eliminates spurious sources of water arising from the clipping of negative moisture values in the non-positive-definite model formulation, leading to the bias reduction.
منابع مشابه
Probabilistic forecasting of shallow, rainfall-triggered landslides using real-time numerical weather predictions
A project established at the National Institute of Water and Atmospheric Research (NIWA) in New Zealand is aimed at developing a prototype of a real-time landslide forecasting system. The objective is to predict temporal changes in landslide probability for shallow, rainfalltriggered landslides, based on quantitative weather forecasts from numerical weather prediction models. Global weather for...
متن کاملThe Wgne Assessment of Short-term Quantitative Precipitation Forecasts
APRIL 2003 AMERICAN METEOROLOGICAL SOCIETY | O f all the weather elements for which forecasts are provided to the public, rainfall is perhaps of the greatest interest. While most people simply want to know whether they will need an umbrella that day, there is growing demand from industry, agriculture, government, and many other sectors for more detailed rainfall predictions. Unfortunately, rain...
متن کاملImpact of a revised convective triggering mechanism on Community Atmosphere Model, Version 2, simulations: Results from short-range weather forecasts
[1] This study implements a revised convective triggering condition in the National Center for Atmospheric Research (NCAR) Community Atmosphere Model, Version 2 (CAM2), model to reduce its excessive warm season daytime precipitation over land. The new triggering mechanism introduces a simple dynamic constraint on the initiation of convection that emulates the collective effects of lower level m...
متن کاملEvaluation of numerical weather prediction model precipitation forecasts for short-term streamflow forecasting purp se
The quality of precipitation forecasts from four Numerical Weather Prediction (NWP) models is evaluated over the Ovens catchment in Southeast Australia. Precipitation forecasts are compared with observed precipitation at point and catchment scales and at different temporal resolutions. The four models evaluated are the Australian Community Climate Earth-System Simulator (ACCESS) including ACCES...
متن کاملRemotely Sensed Soil Moisture over Australia from AMSR-E
Soil moisture can significantly influence atmospheric evolution. However the soil moisture state predicted by land surface models, and subsequently used as the boundary condition in atmospheric models, is often unrealistic. New remote sensing technologies are able to observe surface soil moisture at the scales and coverage required by numerical weather prediction (NWP), and there is potential t...
متن کامل